Most people define virginity as the circumstance that a penis has never entered the vagina. Your hymen could be broken through vigorous physical activity such as horseback riding or gymnastics.

If you are directing water into your vagina at such a high rate of flow that your hymen breaks, you're really overdoing it! I'd have to look this up, but injecting a lot of water at a very high velocity may introduce bacteria and other matter into the uterus through the cervix. I believe you are at a higher risk of PID (pelvic inflammatory disease) if you do too much douching, for example, and I think you could argue that pointing a jet of water straight into the vagina is a very forceful douche. I'd avoid trying to fill up the vagina with a jet nozzle of water. You risk tearing the vaginal wall too. It's all a set up for bacteria to enter damaged and torn tissue.

If it's not pointed up and into your vagina, if it's just like your normal showering, you're fine.